Electrical cutout



May 29, 1945. c. A. Fox 2,376,996

ELECTRICAL CUT-OUT Filed Jan. 30, 1942 2 Sheets-Sheet 1 //v VEN TC B01,421 55 AD/N Fox ATTORNEY ELECTRICAL CUT-OUT Filed Jan. 30, 1942 2Sheets-Sheet 2 ATTORNEY Patented May 29, 1945 ELECTRICAL CUTOUT CharlesAdin Fox, Oakland Village, Mo., assignmto James It. Kearney Corporation,St. Louis, Mo., a corporation of Missouri Application January 30, 1942,Serial No. 428,854

4 Claims.

' This invention relates generally to electrical cutouts and morespecifically to electrical cutouts of the type that include fusibleelements adapted to be ruptured as a result of passage of abnormalelectrical current therethrough to interrupt the electrical circuitswith which the cutouts are electrically associated, the predominantobject of the invention being to provide a cutout of the type referredto above which is of extremely simple construction and arrangement andis capable of performing its intended function in a highly efficientmanner.

The cutout of the present invention in general is of the type of thedevice disclosed in United States Letters Patent No. 2,086,028, grantedon July 6, 1937, in that it includes a simple fuse link structure forproviding an interruptable current path through the cutout, instead ofbeing provided with a relatively complicated mechanical structureproviding a fuse cartridge for that purpose as was true of many switchesand cutouts heretofore known. However, the cutout of the presentinvention differs mechanically from the structure of the device of thepatent referred to above because of the fact that it was designed and isintended particularly for use with electrical circuits carrying currentsof higher amperages.

Fig. l is a side elevation of the improved cutout of the presentinvention, a portion of the fuse link thereof being shown in section.

Fig. 2 is an enlarged, fragmentary horizontal section taken on line 2-2of Fig. 1.

Fig. 3 is a front elevation of the cutout illustrated in Fig. 1.

Fig. 4 is an enlarged, fragmentary view, partly in elevation and partlyin section, of the lower portion of the improved cutout.

Fig. 5 is an enlarged, fragmentary plan view of the outer portion or oneof the contact arms of the improved cutout.

In the drawings, wherein is shown for the purpose of illustration,merely, one embodiment of the invention, A designates the improvedcutout generally. The cutout A includes a suitable inaulator I formed ofporcelain or other suitable electrical insulating material to which issecured a suitable bracket 2 that aids in the attachment of the cutoutto a crossarm or other support.

Supported by the insulator I at the upper end thereof is an upperterminal 3 which is formed of electrical conducting material andincludes a segmental cap portion 4 that embraces a part of the upperportion of the insulator I as shown in Fig. 1. At its opposite sides theportion 4 of the upper terminal 3 is provided with outstanding aperturedlugs 5 through which end portions of a U-shaped rod 6 are extended, saidrod 6 being drawn into embracing relation with respect to a part of theupper portion of the insulator I by nuts I which are applied to theouter ends of the rod and are jammed against the lugs 5 so as tosecurely clamp the upper terminal 3 to said insulator I. The upperterminal 3 includes also a head portion 8 which is formed integral withthe segmental cap portion 4, and extended upwardly from said headportion is an extension 9 of elongated, loop formation, said extension 9having electrically and mechanically attached thereto by means of asuitable connector I0 a conductor Ca which forms a part of theelectrical circuit with which the cutout A is associated.

Secured to and extended outwardly from the upper terminal 3 is an uppercontact, arm II which preferably, though not necessarily, is formed froma single length of heavy wire or rod of a material that is characterizedby being a good conductor of electricity. At its rear end the uppercontact arm II is provided with an upwardly extended loop I2 from thelower portion of which are extended a pair of parallel portions l3 ofthe upper contact arm, said upper contact arm being secured to the headportion 8 of the upper terminal 3 by a bolt I4 whose shank extendsthrough the loop I2 and is seated in a screwthreaded opening formed insaid head portion 8 and whose head portion engages a washer whichcontacts with the outer surface of the loop I2.

The outer end portion of the upper contact arm II is shaped and formedas shown to the best advantage in Fig. 5. That is to say, convergentportions I5 are extended forwardly from the outer portions of theparallel portions I8 of the upper contact arm II. These convergentportions II merge into outwardly curved portions I8 having outer legswhich extend rearwardly, and said outer legs of said curved portions I8merge into divergent portions I! which, at their rear ends, merge intoinwardly curved portions I8. The curved portions ll in turn merge intoforwardly extended portions I! which contact at their forwardend'portions with the convergent portions I5. The outer end portion ofthe upper contact arm II has applied thereto a cap 20 which fixedlyembraces the curved portions I 6 and adjacent portions of the uppercontact arm so as to limit undue spreading of the outer end portion ofsaid upper contact arm. Also, the material or which the upper contactarm is formed is possessed of resiliency which tends to force the outerend portions of the portions is into close contact with the convergentportions i5 and therefore when portions of fuse links are drawn into thetapered crotches 2| between said portions i9 and adJacent portions ofthe parallel legs 13, as will be hereinafter explained, said fuse linkportions will move the forward parts of the portions l9 away from theportions I! so as to cause the fuse link portions to be securely grippedbetween the portions I9 and adjacent parts of the parallel portions I3.

Supported by the lower portion of the insulator i is a lower terminalwhich comprises a member 22 provided with an arcuate face 23 thatcontacts with a portion of the outer surface of said insulator l. Themember 22 is provided with upper and lower strengthening webs 24 andwith a pair of outwardly extended, horizontally spaced arms 23. Also,the member 22 is secured to the insulator I through the instrumentalityof connecting means of the type disclosed by United States LettersPatent No. 2,140,904, granted on December 20, 1938, said connectingmeans comprising a bolt 26 which passes through an opening formedthrough the member 22 and through an alined opening formed through thewall of the hollow insulator i. A washer 21, is engaged by the innerface of the head of the bolt 23, and a nut 28 is mounted on the inner,screwthreaded end portion of the bolt, said nut contacting with a washer29 of substantially V-shape formation which is interposed between saidnut and a portion of the inner face of the wall of the insulator I,Interposed between the washer 21 and a forward face of the member 22 isthe upper looped portion of a spring 30, said spring including portions31 which extend downwardly from said upper, looped portion, a pair ofcoiled portions 32 at the lower end of the spring, and portions 33 thatextend upwardly from said coiled portions and which are free formovement at their upper ends. It is obvious that the bolt, washer, andnut assembly 28-48-29 serves the dual purpose of securing the spring 30in place and connecting the lower terminal to the insulator l theresilient washer 29 acting to absorb strains which in the absence ofsaid washer might crack the material of the insulator.

The lower terminal member 22 has formed thereon a downwardly andrearwardly extended element 34 of loop formation which serves as a meansfor electrically and mechanically connecting to the cutout a conductorCb which forms a part of the electrical circuit with which the cutout isassociated. Connection of the conductor Cb to the element 34 is effectedthrough the use of a suitable connector 35 which embraces a portion ofsaid element and a portion of said conductor.

Pivotally attached to the lower terminal member 22 is a lower contactarm 36 which includes a member 31 that is located at the rear end ofsaid lower contact arm. The member 31 is provided with rearwardlyextended, spaced apart arms 38 that are disposed in overlapping relationwith respect to the spaced arms 23 of the member 22 which provides thelower terminal. The member 31 of the lower contact arm 33 is pivotallyattached to the member 22 of the lower terminal by a pivot pin 39 whichis extended through apertures formed through the spaced arms 23 of themember 22 and the spaced arms 33 of the member 31, said pivot pinpreferably being upset at its opposite ends so as to retain it in place.

Also, a torsional coil spring 43 is arranged in embracing relation withrespect to the pivot pin 83 which tends to swing the member 31downwardly and rearwardly about the pivot pin 33, one end of saidtorsional coil spring ensuing over one of the spaced arms 23 of thelower terminal member 22 and the other endof said torsional coil springengaging over a portion of the member 31 to effect such pivotal movementof said member 31. In addition to the force exerted by the torsionalcoil spring 43 which tends to rotate the member 31, parts of theportions 33 of the spring 33 contact with the rear end of an extension4| formed on said member 31. The upper end portions of the portions 33of the spring 33 tend to move outwardly and therefore an outwardlydirected force is exerted by said spring portions 33 against theextension 4| which likewise tends to swing the member 31 outwardly anddownwardly about the pivot pin 39. Additionally, it is important to notethat the spring 33 is in shunt with the pivotal Joint provided betweenthe spaced arms 23 of the terminal member 22 and the member 31 by thepivot pin 33, and that the upstanding portions 33 of said spring 33 makepoint pressure contact with the extension 4| of said member 31. Becauseof this arrangement a superior conductive path is provided for energypassing between the lower contact arm 33 and the terminal member 22.

The forward portion of the member 31 f the lower contact arm 33 isnarrower than the portion of said member which provides the spaced arms33, and the extension 4| IS a continuation of said narrower, forwardportion which is raised slightly above the upper edges of the spacedarms 33. Also, the forward, narrower portion of the member 31 isprovided with downwardly projected flanges 42 which extendlongitudinally at opposite sides thereof. The forward portion 43 of thelower contact arm 33 follows very closely the arrangement of the uppercontact arm I I. In other words, the forward portion 43 of said lowercontact arm is formed from a single length of heavy wire or rod shapedto provide a loop 44 at the rear end of said arm portion from whichsubstantially parallel, forwardly projected portions 45 are extended.The arm portion 43 is secured to the member 31 by a bolt and nutassembly 43, the bolt 0! which extends through an opening formed throughthe loop 44 at the rear end of said arm portion 43, the loop 44 beingdisposed between the flanges 42 of the forward portion of the member 31.The outer end portion of the lower contact arm 36 is formed inaccordance with the arrangement of the outer end of the upper contactarm II, which arrangement is clearly shown in Fig. 5.

The improved cutout includes a fuse link F which comprises a pair offlexible cables 43 and 41 which are provided at their outer ends withsuitable eyes 43' and 41'. The cables 43 and 41 are spaced apart attheir inner ends and arranged in electrical connection with said cablesand disposed in the space between the spaced To assemble the fuse link Fwith the cutout the cable 41 of the fuse link is drawn deep in one.

asram or other of the crotches of the lower' contact arm whichcorrespond to the crotches II of the upper' contact arm and as a resulta portion corresponding to a portion is of the upper contact arm whichis located at a side of the crotch employed to receive the fuse linkcable will engage said fuse link cable so that it is gripped betweensaid portion and a portion of the adjacent contact arm portion whichcorresponds to a portion ii of the upper contact arm. The fuse link isapplied to the lower contact arm as described with the aid of a suitabletool in the form of a stick having a finger which is extended throughthe eye 46' at the upper end of the fuse link. With the finger of thestick still in engagement with-th eye it of the fuse link, said fuselink is moved upwardly toward the upper contact arm Ii thereby movingthe lower contact arm from the position in which it is shown by dottedlines in Fig. 4 to the elevated position in which said lower contact armis shown by full lines in Fig. 1. When the fuse link has been elevatedto the proper degree the cable 48 of said fuse link is drawn deep in oneor the other of the crotches 2| of upper contact arm I i where it willbe engaged and gripped between the associated portions I9 and it of saidupper contact arm as previously explained. The finger of the stick isthen disengaged from the eye 46 of the fuse link and the cutout is in afused condition and ready for use.

When, in the use of the improved cutout, a fault occurs in the circuitwith which the cutout is associated which is of a character to blow thefuse link, the fusible element 48 of the fuse link F will be ruptured.This will free the lower contact arm 38 from the restraint imposedthereon by the unruptured fuse link with the result, that the coilspring 30 and the torsional spring ii will swing the outer end portionof said lower contact arm 36 rapidly in a downwardly, extended arc of acirale to the position in which said lower contact arm is shown bydotted lines in Fig. 4. The described downward movement of the lowercontact arm 36 will quickly pull the ruptured ends of the fusibleelement 48 apart whereby an are formed between said ruptured ends ofsaid fusible element will be extinguished within the tube 49 of the fuselink.

It is important to note that the lateral gripping action to whichportions of the cables 48 and 41 of the fuse link F are subjected by theportions i9 and ll of the upper contact arm ii and by correspondingportions of the lower contact arm 38, provide good electrical connectionbetween said upper and lower contact arms and the fuse link F. As aresult of this situation it is not necessary to subject the fuse link toexcessive tension in order to obtain the desired good electricalconnection between the fuse link and the upper and lower contact arms aswould be the case if it were necessary to draw the buttons a and 41a, orsimilar elements, at the outer ends of the cables 46 and 41 into closecontact with the upper and lower contact arms to obtain properelectrical connection between said contact arms and the fuse link.

I claim:

1. An electrical cutout comprising a supporting structure includingspaced terminals, spaced contact arms associated respectively with saidspaced terminals, pivot means for attaching one of said contact arms tothe terminal with which it is associated for pivotal movement, springmeans for subjecting said pivotally supported contact arm to pivotalmovement, said spring means being characterized by being formed ofmaterial which is a good conductor of electrical energy and forming apart of the direct current path between the pivotally supported contactarm and its supportin: terminal, and said spring means comprising asubstantiallyvertically disposed resilient element of substantiallyU-shaped formation a portion of which is secured to the terminal withwhich said pivotally supported contact arm is associated and anotherportion of which contacts with a portion of said pivotally supportedcontact arm and exerts a force thereagainst which is directedtangentially of said pivot means, a torsional coil spring which embracessaid pivot means and aids said spring means in subjecting said pivotallysupported contact arm to pivotal movement, and a fuse link engaged byouter end portions of said contact arms and maintained under tension bythe tendency of said spring means and said torsional coil spring tosubject said pivotally supported contact arm to pivotal movement.

2. An electrical cutout comprising a supporting structure includingspaced terminals, spaced contact arms associated respectively with saidspaced terminals, one of said spaced contact arms being adapted formovement toward and away from the other of said spaced contact arms,each of said spaced contact arms being formed from resilient materialshaped to provide a forwardly extended portion, a portion which extendsrearwardly from the outer end of said forwardly extended portion, and aforwardly projected gripping portion which is disposed between saidforwardly extended portion and said rearwardly extended portion forresilient movement toward and from said forwardly extended portion, anda fuse link engaged by the outer end portions of said contact arms andmaintained under tension by the tendency of said movable contact arm tomove in a direction away from the other contact arm, said fuse linkhaving portions which are gripped between said forwardly extendedportions of the contact arms and said forwardly'projected grippingportions thereof.

3. An electrical cutout comprising a supporting structure includingspaced terminals, spaced contact arms associated respectively with saidspaced terminals, one of said spaced contact arms being adapted formovement toward and away from the other of said spaced contact arms,each of said spaced contact arms being formed from resilient materialshaped to provide a pair of substantially parallel forwardly extendedportions, portions which extend rearwardly from the outer ends of saidforwardly extended portions, and forwardly extended gripping portionswhich are disposed between said forwardly extended portions and saidrearwardly extended portions for resilient movement toward and from saidforwardly extended portions, and a fuse link engaged by the outer endportions of said contact arms and maintained under tension by thetendency of said movable contact arm to move in a direction away fromthe other contact arm, said fuse link having portions each of which isgripped between one or the other of said associated forwardly extendedportions and forwardly projected gripping portions of each of saidcontact arms.

4. An electrical cutout comprising a supporting structure includingspaced terminals, spaced contact arms associated respectively with saidspaced terminals, one of said spaced contact arms being adapted formovement toward and away from the other of said spaced contact arms,each of said spaced contact arms being formed from a single iengthofresilient material shaped to provide a pair of substantially parallelforwardly extended portions, portions which extend rearwardiy from theouter ends of said forwardly extended portions, and forwardly extendedgrippin: portions which are disposed between said forwardly extendedportions and said rearward- 1y extended portions for resilient movementtoward and from said forwardly extended pormenace tiona. a fuse linkengaged by the outer end portiona ofaaid contact arms and maintainedunder tension by the tendency of said movable contact arm to move in adirection away from the other contact arm. said {use link havin portionseach of which is :ripped between one or the other of said aaeooiatedforwardly extended'portiona and forwardiy'projected :rip-' pin: portionsof'e'ach of said contact arms, and a cap applied'to the outer end ofeach contact arm to prevent undue spreading thereof.

1 CHARLIE ADIN FOX.

